Method of manufacturing tapered beams



METHOD OF MANUFACTURING TAPERED BEAMS Filed May 10, 1950 2 FIG. l.

INVENTOR. WALTER F. BURKE CM/WCW ATTORNEYS.

Patented Nov. 11, 1952 METHOD OF MANUFACTURING TAPERED' BEAMS Walter F. Burke, St. Louis, Mo., assignor to Mc- Donnell Aircraft Corporation, St. Louis, Mo., a

corporation of Maryland Application May 10, 1950, Serial No. 161,152

This invention relates to the manufacture of structural elements for aircraft and is particularly directed to the manufacture of tapered beams or spars therefor.

The primary object of the invention is to produce a tapered I-beam or spar from a uniform section I-beam having an enlarged web portion.

Another object of the invention is to produce a tapered I-beam or spar requiring only a minimum of metal working or machining.

A further object of the invention is to produce a flanged tapered beam whose parts have a desired thickness and formed from a uniform section flanged beam provided with a bulbous web.

A still further object of the invention is to produce a tapered beam from a uniform section I-beam having a bulbous Web in which the flanges of the I-beam retain their original size as the bulbous web is forged for tapering the beam.

The invention consists in forming an I-beam by extruding, rolling, or forging so that the web thereof is enlarged, after which a suitable length is cut therefrom and the web forged to reduce its section at one end of the beam for tapering thereof, and then machining the web to the desired thickness and also machining the flanges of the beam to the proportions desired, should the latter be necessary.

In the drawings:

Fig. 1 is a side elevational view of an I-beam made in accordance with the invention,

Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1,

Fig. 3 is a side elevational view of the beam after a metal forming operation,

Fig. 4 is a sectional view taken substantially along the line 4-4 of Fig. 3,

Fig. 5 is a sectional view taken substantially along the line 5-5 of Fig. 3,

Fig. 6 is a side elevational view of the I-beam after it has been machined,

Fig. 7 is a sectional view taken along the line 17 of Fig. 6; and

Fig. 8 is a sectional view taken substantially along the line 88 of Fig. 6.

This invention is practiced on the structural member illustrated in Fig. l of the drawings in which the numeral I indicates an I-beam having a comparatively large flange 2 on one edge thereof and a smaller flange 3 on the opposite edge. The web 4 of the I-beam is made bulbous, as particularly shown in Fig. 2. The I-beam is preferably made of soft, ductile metal and the 2 Claims. 01129-155) 2 shape illustrated may be extruded, rolled, or forged as desired.

A suitable length is out from a stock beam and the bulbous Web 4 then subjected to a forging or pressing operation for the purpose of changing the section thereof in order to form a tapered I-beam which is particularly useful in aircraft construction. The foregoing of the bulbous web is continued until the beam is made substantially the desired size. The amount of forging done on the web varies from one end of the beam to the other in order that the web section may taper, thereby tapering the beam in direct proportion. The forging operation causes the flanges 2 and 3 to be spread apart, the bulbous section of the beam gradually increasing toward the smaller end thereof so that it will be substantially the same as that illustrated in Figs. 2 and 5. When the forging or pressing operation has been completed on the bulbous web, the partially completed tapered I-beam is then subjected to .a machining operation. During this operation the web of the beam is reduced to its desired section, which may be either uniform or variable, as the load requirements to be imposed on the beam may dictate. The forging operation on the web may have a tendency to distort flanges 2 and 3, and they may also be machined in order to present a clean, smooth surface to the cooperating structure of the aircraft. The machining may be done by a planer, a miller, a shaper, or any other suitable machining tool, which machining will remove any unevenness in the surfaces of the web section or flanges resulting from the forging or pressing operation.

The method of producing a tapered I-beam as described, is a material advance in the art over the methods of manufacture previously practiced. One of these methods was to cut a tapered I-beam from a solid extruded or rolled section as large as the maximum size of the tapered beam, and therafter machining the excess material for forming the flanges and the web.

The above described method eliminates the use of costly die work that would be necessary in a rolling or forging operation for forming a tapered I-beam. Applicant's method has also reduced the amount of material wasted, as well as the time necessary for manufacturing a tapered I-beam. The over-all economy in material and labor very materially reduces the unit cost of the completed tapered I-beam.

What I claim is:

1. The method of manufacturing a tapered beam member from a beam having parallel 3 flanges connected by a bulbous web section, which comprises forging the bulbous section progressively and in varying amounts from one end toward the opposite end while allowing the opposite margins to move laterally and freely into a tapering relation varying from one end to the opposite end and proportionately with the forging of the bulbous section, and machine finish ing the web section to final desired dimensions.

2. The method of manufacturing a tapered beam member from a beam having parallel flanges connected by a bulbous web section, which comprises forging the bulbous section progressively and in varying amounts from one end toward the opposite end while allowing the opposite margins to move laterally and freely into a tapering relation varying from one end to the opposite end proportionately with the forging of the bulbous section, and machine finishing the flanges to final desired dimensions.

WABTER F. BURKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 679,759 Lanz Aug. 6, 1901 1,656,846 Witherow 'Jan. 17, 1928 1,746,520 Brody Feb. 11, 1930 1,814,593 Gersman July 14, 1931 1,857,582 Bender May 10, 1932 FOREIGN PATENTS Number Country Date 673,211 Germany Mar. 17, 1939 

